Systems and methods for updating firmware or other critical configuration data in scalable distributed systems are provided. Such systems and methods can include (1) a master controller receiving (a) a firmware update file that is divided into a plurality of packets and (b) a metadata file that is associated with the firmware update file and (2) a first one of a plurality of slave controllers receiving the metadata file and, responsive thereto, updating a local peer table to include entries for the master controller and a group of the plurality of slave controllers that are available to share any of the plurality of packets and downloading each of the plurality of packets from a combination of the master controller and the group of the plurality of slave controllers.